In general, there is a constant need to increase the operating efficiency of power generation systems. By increasing the efficiency of such power generation systems, capital costs may be reduced, more power may be generated, and there may be a reduction of possible adverse impacts on the environment through a reduction in the amount of waste heat that must ultimately be absorbed by the environment. In other industrial processes, an excess amount of heat may be generated as a byproduct of the process. In many cases, such waste heat is normally absorbed by the environment through use of waste heat devices such as cooling towers.
Several known systems are addressed in the prior art, which includes the following. U.S. Pat. No. 3,208,229 titled “Vortex Tube” by Fulton relates to the design and construction of vortex tubes capable of emitting colder and hotter streams of gas, operating more efficiently, being more compact and more cheaply manufactured. U.S. Pat. No. 5,327,728 by Tunkel is a method for the design of a vortex tube for energy separation, the vortex tube having a long tube, a diaphragm closing one end of the tube having a hole in the center, one or more tangential nozzles piercing the tube just inside the diaphragm, and a throttling valve at the far end of the tube. U.S. Pat. No. 5,561,982 titled “Method for energy separation and utilization in a vortex tube which operates with pressure not exceeding atmospheric pressure” by Tunkel, et al. utilizes a vacuum pump to achieve the pressurized solution to discharge a cool stream connected though the heat exchanger provided to utilize as a cool duty and produce a hot stream at the far end of the tube for a hot duty. U.S. Pat. No. 6,964,168 titled “Advanced Heat Recovery and Energy Conversion Systems for Power Generation and Pollution Emissions Reduction, and Methods of Using Same” by Pierson are various systems and methods for producing mechanical power from a heat source. U.S. Pat. No. 6,318,065 titled “System for Chilling Inlet Air for Gas Turbines” by Pierson is a method and apparatus for chilling water delivery to an inlet air chiller of a gas turbine to lower the temperature of inlet air. This patent does anticipate the useful application of an ORC and refrigerant.
There are several systems employed in various industries to produce useful work from a heat source. The classic Rankine cycle can be utilized to produce power, but this process is complex. The Rankine cycle involves isothermal (constant temperature) boiling as the working fluid, i.e., water, is converted from a liquid to a vapor state. Typically, waste heat from gas turbines or other, similar, high quality heat sources can be recovered using steam at multiple temperatures and pressures. Multiple operating levels are required because the temperature-enthalpy profile is not linear.
Similar to the classic Rankine cycle, an Organic Rankine cycle utilizes a low temperature working fluid in a closed cycle such as isoButane or isoPentane in place of steam in the classic cycle. The system remains complex and is highly inefficient at low operating temperature differentials. There is a need to simplify the Rankine cycle process while having the capability to recover more heat and to recover heat from a low quality heat source while amplifying its temperature-enthalpy. The present invention is intended to solve these problems as the invention is directed generally to low temperature power generation, and more specifically to the use of segregated energy streams to achieve a high efficiency vapor power Organic Rankine Cycle.